Straight bar knitting machines

ABSTRACT

A yarn carrier system for fully fashioned straight bar knitting machines wherein each yarn carrier device comprises a carrier box slidable relative to its co-acting carrier rod, a drive bracket secured to said carrier rod, and centralizing spring means arranged between said carrier box and said drive bracket to permit of limited excess movement of said carrier rod and said drive bracket relative to said carrier box.

United States Patent Swanwick [451 Apr. 25, 1972 [54] STRAIGHT BAR KNITTING MACHINES [56] References Cited [72] Inventor: Barry Frederick Swanwick, Melton Mow- UNITED STATES PATENTS bray, England 1 2,623,371 12/1952 Wxckardt ..66/126 R X Assigneei Monk n in A hfiel Lim d 2,670,619 3/1954 Zimic et a1.. ..66/126 R Ashfield, Nottinghamshire, England 2,688,861 9/1954 Fegley ....66/ 126 R [22] Filed: June 1 1970 3,364,703 1/l968 Krause ..66/l26 R [21] App]. No.: 42,215 Primary Examiner-Louis K. Rimrodt Attorney-Baldwin, Wight & Brown [30] Foreign Application Priority Data [57] ABSTRACT June 1969 Grea Britain 28,295/69 A yarn carrier system for fully fashioned straight bar knitting machines wherein each yarn carrier device comprises a carrier 1.8. CI- R box Slidable relative to its yacting carrier rod a drive [51] Ill!- Cl. bracket secured to said carrier rod and centralizing pring [58] Field Of Search ..66/l26 R, 130 means arranged between said carrier box and said drive bracket to permit of limited excess movement of said carrier rod and said drive bracket relative to said carrier box.

12 Claims, 4 Drawing Figures SHEET 2 [IF 3 m F1 min n n n.

PATENTEDAPR 25 i972 STRAIGHT BAR KNITTING MACHINES This invention relates to straight bar knitting machines and is concerned with improved means for laying the yarn across the knitting elements particularly in muti-head machines.

In multi-head straight bar knitting machines, the yarn carriers are fixed to carrier rods which extend lengthwise of the machine. A plurality of such rods are generally provided and each has mounted thereon several yarn carrier devices which 1 are arranged one to each knitting head and in the same position relative to each knitting head. Usually, each carrier rod is reciprocated lengthwise of the knitting heads and means are provided to stop movement thereof, and thus of the yarn carriers, precisely at the terminal positions corresponding to the selvedges of the garment piece being knitted.

One method of achieving this precise terminal positioning is by means of the carrier chain draw mechanism disclosed in the copending application, Ser. No. 807,658 of Barry'F. Swanwick et al., filed Mar. 17, 1969, now US. Pat. No. 3,575,017, granted Apr. 13, 1971. However, although this method is satisfactory, it is expensive. Furthermore, this method suffers the disadvantage that wear in the mechanism creates a condition in which the traversing masses override their driving and decelerating forces, and this can result in what is known as slamming when the carrier rod reaches its terminal position as determined by the selvedge screws.

Another known method is to drive the carrier rod by means of a friction box which is caused to slip when the carrier rod impacts against the selvedge stops provided on the selvedge or fashioning screw nut housings. This method has the disadvantage that considerable forces have to be dissipated and the v slamming condition hereinbefore referred to severely inhibits the speed of operation of the machine.

A still further known method is to fix each yarn carrier onto a light weight box which is slidably mounted on the carrier rod and iscaused to reciprocate with it by means of friction pads. In this case, selvedge stops provided on the selvedge or fashioning screws are arranged over each knitting head and each friction carrier box impacts against its own individual right-hand and left-hand selvedgestops. This method has the advantage over the previously described methods that the slamming condition is considerably reduced since the mass of the yarncarrier box is substantially reduced. However, a disadvantage of this method is the need for latches to be provided for each box to be retained in its extreme selvedge position, and to facilitate widening.

It will be appreciated that the traversing of large masses does not, in itself, create problems in designing and operating yarn laying means, but that problems do exist in achieving precise terminal positioningof the yarn'carriers particularly when operating at high speed. It is therefore among the objects of the present invention to provide a yarn laying system which overcomes, or substantially reduces, these problems and also avoids, or substantially reduces, the disadvantages of the known methods hereinbefore referred to.

According to the present invention, there is provided a yarn carrier system for multi-head straight bar knitting machines, comprising at least one reciprocatory carrier rod mounting at least one yarn carrier device in respect of each knitting head, and adjustable stop means for limiting the extent of reciprocatory movement of the yarn carrier devices, wherein each yarn carrier device incorporates centralizing or overload means which permit of limited excess traversing movement of the carrier rod to take place, thereby eliminating the need for precise terminal positioning of ,all the heavy reciprocating masses provided by the carrier rods and the yarn carrier devices.

Preferably, the centralizing or overload means comprise a compression spring arranged between a part of the carrier box which is fixed to the carrier rod and a part of the carrier box which is slidably mounted on the carrier rod.

Thus, the invention provides light weight yarn carrier devices incorporating yarn guides and mounted on a' reciprocatory and relatively heavy, carrier rod which is accelerated from rest at one selvedge position and decelerated to rest at the other selvedge position, the yarn carrier devices being arranged and constructed so as to permit of relative movement between the yarn guides and the carrier rod so that the latter may, but not necessarily, travel slightly beyond the desired terminal position of the yarn carrier guides.

The invention is illustrated by way of example in the accompanying drawings in which,

FIG. 1 is a cross section through part of a straight bar knitting machine showing the relative positions of a plurality of yarn carriers,

FIG. 2 is a view in the direction of the arrow 2 of FIG. 1 showing only those parts which are necessary to give a clear understanding of the invention,

FIG. 3 is a front elevation, on an enlarged scale, of a yarn carrier device according to the invention, and

FIG. 4 is a section on the line 4 4 of FIG. 3.

Referring to the drawings, and particularly to FIG. 1, there is shown part of a straight bar knitting machine incorporating a plurality of yarn carrier boxes 1 having yarn guides 2.

The drawings show certain parts of the main supporting framework of the machine and those parts are all indicated by the reference F.

The yarn guides 2 are positioned to co-operate with a series of needles 3 supported for limited angular movement in a needle bar 4. A series of sinkers 5 slidable in tricks in a sinker bed 6 mounted on a frame member F are arranged to co-operate -with the needles 3 in known manner. The sinkers 5 are operated by a slurcock 7 via jacks 81, the latter being urged into an inoperative position by means of springs 9. In addition, a series of knock-over bits 10, supported on a knock-over bar 11, are provided to co-operate with the needles 3, again in well-known manner.

Referring now particularly to FIG. 2, the yarn carrier boxes 1 are each mounted on a carrier rod 12. The carrier rods 12 extend lengthwise of a knitting bay KB and into a control bay CB of the machine where they are connected to drive means (not shown) which serve, in well-known manner, to effect lengthwise reciprocation thereof and thus cause the carrier boxes 2 to reciprocate relative to the needles 3. In this respect,

it will be appreciated that the carrier rods 12 extend over any desired number of knitting bays KB and each rod 12 has attached thereto a yarn carrier box 1 in :respect of each knitting bay.

Each carrier box 1 comprises a base member 13 having fixed thereto, as by screws 14, two spaced bracket plates 15, the base member and the bracket plates being slidable relative to the rod .12. The base 13, between the bracket 15, is provided with a downwardly depending lug 16 to which the yarn guides 2 is attached by means of screws 17. A yarn feed tube 18 is provided to co-act with the guides 2 to prevent entanglement of the yarn.

The bracket plates 15 are provided with bosses 19 to receive opposite ends of a spindle 20. The spindle 20 is screwthreaded at its ends, each of which ends is provided with a lock nut 21 and a stop member 22 to permit of adjustment thereof relative to the carrier box. Slidably mounted on the spindle 20 are two spaced sleeves 23 one end of each of which is adapted to bear against one of the bosses 19 and the other end of each of which is formed with a transverse projection 24. A compression spring 25 is also mounted on the spindle 20 and is arranged to bear against said other ends of the sleeves 23 to bias them into contact with the bosses 19. The force exerted by the spring 25 is preferably of the order of one-half kg.

A drive bracket 26 having two spaced lugs or projections 27 is secured, as by screws 28, to the carrier rod 12 and is positioned so that the lugs or projections 27 respectively enter into engagement with the projections 24 of the sleeves 23. Thus, it will be appreciated that the carrier box, if not otherwise influenced, is held in a central position relative to the drive bracket 26 which is fixed to the carrier rod 12.

Two stop mechanisms 29 and 290 are provided in the or each knitting bay KB in order to dictate the length of the stroke of the or each yarn carrier box 1. Each stop mechanism comprises a block 30 and stop bar 31 which is slidable in an opening formed in the block 30. The block 30 adjacent one end is fixedly secured, by means ofa screw 32, to an adjusting shaft 33 extending lengthwise of the machine. The other end of the block 30 is bifurcated to slidably engage a fixed guide rod 34 which extends lengthwise of the machine between main frame members F.

In order to adjust the position of the stop mechanism 29 according to the required width of the fabric being knitted, the adjusting shaft 33 extends into the control bay CB where it is fixed to'a nut housing 35 mounted on a fashioning screw 36. To move the nut housing 35 lengthwise of the screw 36, and thus also to adjust the position of the stop mechanism 29, the screw is rotated, in known manner, by means of racks 37 and 38 actuated by co-acting racking pawls 39, 40. The rack and pawl 37, 39 turns the screw 36 in one direction and the rack and pawl 38, 40 turns the screw 36 in the opposite direction. Actuation of the racking pawls is effected, in well-known manner, via a linkage system from .the main cam shaft of the machine.

It will be appreciated that the stop mechanism 29a is mounted and adjusted in the same manner, and by similar means, as that of the stop mechanism 29 except that the hand of the fashioning screw is the opposite to that of the fashioning screw 36 so that the stop mechanisms move in opposite directions to one another. It will further be appreciated that the nut housings and fashioning screws form part of a mechanism normally provided in fully fashioned straight bar knitting machines in order to position the width control means and the fashioning mechanisms and that they are additionally used in the present case to control the stops 29 and 290.

In FIGS. 1 and 2 of the drawings the stop bar 31 is in a position where it controls the length of the stroke of one yarn carrier 1. However, in order to control more than one yarn carrier, the stop bar 31 is provided to be adjustable. For this purpose the stop bar 31 is provided at its free end with two upstanding prongs 41 which slidably engage a shaft 42 extending lengthwise of the knitting bay. The shaft 42 is fixedly connected, via brackets 43 and 44, to an actuator shaft 45 which extends into the control bay CB where it has fixed thereto a link 46. Pivotally connected to the link 46 is an actuating rod 47 which is operated by, or from, the main cam shaft of the machine to move in a vertical direction to impart angular movement to the links 43, 44 and thus cause relative movement between the stop bar 31 and the block 30. The vertical movement of the actuating rod 47, and thus the extent of movement of the stop bar 31, is controlled to co-operate with one or more yarn carriers 1 according to requirements.

In operation, having adjusted the stop bar 31, and the lengthwise position of the stop mechanisms 29 and 29a, the yarn carrier traversing means are operated in the normal way. When the yarn carrier box with its yarn guide 2 engages, as illustrated in FIG. 2, its co-acting stop bar 31 and stops, the

drive bracket 26 and thus also the carrier rod 12 will be permitted, against the action of the spring 25, to travel a limited distance beyond the stop bar 31. Thus, it will be appreciated that the arrangement provides precise terminal positioning of the yarn carrier box 1 and the yarn guide 2, and also permits the heavy traversing mechanism to be driven in excess of the garment piece width so that the excess motion can be conveniently lost without affecting the terminal positioning factor.

A further advantage of the arrangement of the invention is that the yarn carrier box 1, when in a stationary position adjacent the selvedge of the garment piece, is held in that position by the force of the compression spring thereby eliminating the need for latches which are normally required for that purpose.

Furthermore, in the garment piece widening process known as widening-in-the-course, the stop mechanisms 29 and 29a are moved outwards a distance equivalent to one needle pitch by racking the selvedge screws and the yarn carriers are moved outwards simultaneously with the stop mechanisms. In

this process, the simultaneous movement of the yarn carriers with the stop mechanisms is normally effected by the latches hereinbefore referred to which retain the carrier boxes in their positions adjacent the stop mechanisms. In the present arrangement however, the compression spring 25 of the yarn carrier is capable of exerting sufficient force to cause the yarn carrier box to follow the movement of its co-acting stop mechanism.

The yarn carrier arrangement of the present invention may be applied to any yarn laying system but it can with particular advantage be applied to the slur draw mechanism which is the subject of the aforementioned US. Pat. No. 3,575,017 as a cheap and simple replacement of the carrier chain draw arrangement.

What I claim is:

l. A yarn carrier system for multi-head fully fashioned straight bar knitting machines, comprising at least one reciprocatory carrier rod mounting at least one yarn carrier device in respect of each knitting head, and adjustable stop means for limiting the extent of reciprocatory movement of each yarn carrier device, wherein each yarn carrier device comprises a carrier box mounting a yarn guide which box is slidably mounted-on its co-acting carrier rod, a drive bracket fixedly secured to said carrier rod, and centralizing or overload means arranged between the carrier box and the drive bracket for permitting the carrier rod to have limited excess traversing movement beyond the terminal positions dictated by the stop means of the yarn carrier box.

2. A system as claimed in claim 1, in which the centralizing or overload means comprise a spring means for biasing the carrier box into a central position relative to the drive bracket.

3. A system as claimed in claim 2, in which said spring means is a compressionspring and each yarn carrier device comprises a carrier box formed with two spaced bosses housing a spindle on which said compression spring is supported, a sleeve member slidably mounted on the spindle between each end of the compression spring and the respective bosses of the carrier box, the inner end of each sleeve member being provided with a projection which enters into engagement with a co-acting projection or lug formed on the drive bracket.

4. A system as claimed in claim 3 in which the stop means comprise a pair of stop barseach mounted in a support block, the support blocks being adjustably mounted for lengthwise movement relative to the needle bed of each knitting bay.

5. A system as claimed in claim 4, including means for effecting lengthwise movement of said support blocks in opposite directions, which means comprise fashioning screws mounting nut housings and racking means arranged to rack said screws in opposite directions.

6. A system as claimed in claim 5, in which, where a plurality of yarn carrier devices are provided in respect of each knitting bay, each of said stop bars is adapted to be adjusted relative to its co-acting support block.

7. A system as claimed in claim 6, in which the support blocks are pivotally connected to a shaft extending lengthwise of the machine, said shaft being connected, as by spaced links, to an actuator shaft extending parallel with the first shaft, means being provided to impart angular movement to the actuator shaft and thus sliding movement of the stop bars in their respective support blocks.

8. A system as claimed in claim 1 in which the stop means comprise a pair of stop bars each mounted in a support block, the support blocks being adjustably mounted for lengthwise movement relative to the needle bed for each knitting bay.

9. A system as claimed in claim 8, in which, where a plurality of yarn carrier devices are provided in respect of each knitting bay, each of said stop bars is adapted to be adjusted relative to its co-acting support block.

10. A system as claimed in claim 2 in which the stop means comprise a pair of stop bars each mounted in a support block, the support blocks being adjustably mounted for lengthwise movement relative to the needle bed for each knitting bay.

11. A system as claimed in claim 10, in which, where a plurality of yarn carrier devices are provided in respect to each knitting bay, each of said stop bars is adapted to be adjusted relative to its co-acting support block.

12. A system as claimed in claim 4, in which, where a plu- 5 rality of yarn carrier devices are provided in respect to each knitting bay, each of said stop bars is adapted to be adjusted relative to its co-acting support block. 

1. A yarn carrier system for multi-head fully fashioned straight bar knitting machines, comprising at least one reciprocatory carrier rod mounting at least one yarn carrier device in respect of each knitting head, and adjustable stop means for limiting the extent of reciprocatory movement of each yarn carrier device, wherein each yarn carrier device comprises a carrier box mounting a yarn guide which box is slidably mounted on its co-acting carrier rod, a drive bracket fixedly secured to said carrier rod, and centralizing or overload means arranged between the carrier box and the drive bracket for permitting the carrier rod to have limited excess traversing movement beyond the terminal positions dictated by the stop means of the yarn carrier box.
 2. A system as claimed in claim 1, in which the centralizing or overload means comprise a spring means for biasing the carrier box into a central position relative to the drive bracket.
 3. A system as claimed in claim 2, in which said spring means is a compression spring and each yarn carrier device comprises a carrier box formed with two spaced bosses housing a spindle on which said compression spring is supported, a sleeve member slidably mounted on the spindle between each end of the compression spring and the respective bosses of the carrier box, the inner end of each sleeve member being provided with a projection which enters into engagement with a co-acting projection or lug formed on the drive bracket.
 4. A system as claimed in claim 3 in which the stop meanS comprise a pair of stop bars each mounted in a support block, the support blocks being adjustably mounted for lengthwise movement relative to the needle bed of each knitting bay.
 5. A system as claimed in claim 4, including means for effecting lengthwise movement of said support blocks in opposite directions, which means comprise fashioning screws mounting nut housings and racking means arranged to rack said screws in opposite directions.
 6. A system as claimed in claim 5, in which, where a plurality of yarn carrier devices are provided in respect of each knitting bay, each of said stop bars is adapted to be adjusted relative to its co-acting support block.
 7. A system as claimed in claim 6, in which the support blocks are pivotally connected to a shaft extending lengthwise of the machine, said shaft being connected, as by spaced links, to an actuator shaft extending parallel with the first shaft, means being provided to impart angular movement to the actuator shaft and thus sliding movement of the stop bars in their respective support blocks.
 8. A system as claimed in claim 1 in which the stop means comprise a pair of stop bars each mounted in a support block, the support blocks being adjustably mounted for lengthwise movement relative to the needle bed for each knitting bay.
 9. A system as claimed in claim 8, in which, where a plurality of yarn carrier devices are provided in respect of each knitting bay, each of said stop bars is adapted to be adjusted relative to its co-acting support block.
 10. A system as claimed in claim 2 in which the stop means comprise a pair of stop bars each mounted in a support block, the support blocks being adjustably mounted for lengthwise movement relative to the needle bed for each knitting bay.
 11. A system as claimed in claim 10, in which, where a plurality of yarn carrier devices are provided in respect to each knitting bay, each of said stop bars is adapted to be adjusted relative to its co-acting support block.
 12. A system as claimed in claim 4, in which, where a plurality of yarn carrier devices are provided in respect to each knitting bay, each of said stop bars is adapted to be adjusted relative to its co-acting support block. 